The present invention generally pertains to radar sytems and is particularly directed to an improvement in a monopulse radar system.
In monopulse radar systems an arithmetic matrix is coupled to an antenna for providing pulsed information signals in response to the radar signals transmitted and received by the antenna. These information signals include a sum signal, an azimuth difference signal and an elevation difference signal. The system further includes an azimuth phase comparator for comparing the sum signal to the azimuth difference signal to provide an azimuth error signal, and an elevation phase comparator for comparing the sum signal to the elevation difference signal to provide an elevation error signal.
However, the information signals provided by the arithmetic matrix are RF (radio frequency) signals, whereas the phase comparators typically are designed for processing IF (intermediate frequency) signals.
Accordingly in a typical prior art monopulse radar system, a plurality of parallel channels, each including a mixer and/or an IF amplifier and/or a mixer-IF amplifier combination, simultaneously process the RF information signals in order to provide IF information signals to the phase comparators. In such prior art systems it is necessary that these parallel channels precisely track one another both in amplitude variations and in phase in order to provide information signals to the phase comparators that have the same phase and amplitude relationship as the information signals provided from the arithmetic matrix. Such precision is not readily attained, and as a result, the typical prior art monopulse radar systems are not always reliable.